dot versions of folder.jpg do not show up as thumbnails on volume root, unless explicilty specified in th-covers

Hi :)

The docs mention:

images with the following names (see --th-covers) become the thumbnail of the folder they're in: folder.png, folder.jpg, cover.png, cover.jpg

if you enable file indexing, it will also try those names as dotfiles (.folder.jpg and so), and then fallback on the first picture in the folder (if it has any pictures at all)

I have file indexing enabled (e2dsa+e2ts) without an explicit --th-covers list, and indeed, when I put either a folder.png or a .folder.png into a directory - it shows up as a thumbnail. (Though I think .folder.png required me to reload copyparty once?)

With that, If I put folder.png into the root of a volume, it also works as expected. But .folder.png in the root of a volume does not work "automatically". You can test this by renaming folder.png to .folder.png back and forth. It works fine in an inner folder, but not in the volume root.

However, it works fine when adding .folder.png to the --th-covers list explicitly.

Server details (if you're NOT using docker/podman)

remove the ones that are not relevant:

• what copyparty did you grab: sfx.py
• how you're running it: systemd-service
• run copyparty with --version and grab the last 3 lines (they start with copyparty, CPython, sqlite) and paste them below this line:

copyparty v1.19.21 "usernames" (2025-12-02)
  CPython v3.13.5 on Linux64 6.12.48 [GCC 14.2.0]
   sqlite 3.46.1*1 | jinja 2.11.3 | pyftpd 1.5.10 | tftp 0.4.0

config:

  [global]
  name: Gremy Data
  shr: /shares
  e2dsa
  e2ts

  [/]
    /srv/copyparty/
    accs:
      r: *
    flags:
      daw

  [accounts]
    testman: whatev

  [/test]
    /srv/copyparty/test
    accs:
      rwmda.: testman